U.S. patent number 11,013,081 [Application Number 17/081,453] was granted by the patent office on 2021-05-18 for continuous light dimming circuit.
The grantee listed for this patent is LONGHORN INTELLIGENT TECH CO., LTD. Invention is credited to Shaofeng Huang, Yangyang Luo, Haitao Yang, Lin Yang.
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United States Patent |
11,013,081 |
Yang , et al. |
May 18, 2021 |
Continuous light dimming circuit
Abstract
A light dimming circuit has a continuous dimming function that
includes a power supply and a light source module formed as a lamp.
A power switch is connected to a power supply and receives a user
input when the user turns on and turns off power. A light source
drive circuit is connected to the power switch and the light source
module. The light source drive circuit detects a switch on time and
a switch off time, generates a light source drive signal according
to the switch on time and the switch off time, and saves the light
source drive signal and drives the light source module to
illuminate. The light source drive signal controls a brightness of
the light source module. The brightness of the light source module
is adjusted to provide a continuous dimming function according to
the switch on time and the switch off time.
Inventors: |
Yang; Haitao (Shenzhen,
CN), Huang; Shaofeng (Shenzhen, CN), Yang;
Lin (Shenzhen, CN), Luo; Yangyang (Shenzhen,
CN) |
Applicant: |
Name |
City |
State |
Country |
Type |
LONGHORN INTELLIGENT TECH CO., LTD |
Shenzhen |
N/A |
CN |
|
|
Family
ID: |
75910352 |
Appl.
No.: |
17/081,453 |
Filed: |
October 27, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H05B
47/20 (20200101); H05B 47/16 (20200101); H05B
45/325 (20200101); H05B 45/10 (20200101); Y02B
20/40 (20130101) |
Current International
Class: |
H05B
45/325 (20200101); H05B 47/16 (20200101); H05B
47/20 (20200101); H05B 45/10 (20200101) |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: A; Minh D
Attorney, Agent or Firm: Cheng; Clement
Claims
The invention claimed is:
1. A light dimming circuit having a continuous dimming function
comprising: a. a power supply; b. a light source module formed as a
lamp; c. a power switch, wherein the power switch is connected to a
power supply and configured to receive a user input when the user
turns on and turns off power; d. a light source drive circuit,
wherein the light source drive circuit is connected to the power
switch and the light source module, wherein the light source drive
circuit is configured to: i. detect a switch on time and a switch
off time; ii. generate a light source drive signal according to the
switch on time and the switch off time; iii. save the light source
drive signal; and iv. drive the light source module to illuminate,
wherein the light source drive signal controls a brightness of the
light source module, wherein the brightness of the light source
module is adjusted to provide the continuous dimming function
according to the switch on time and the switch off time, wherein
the light dimming circuit further comprises: a. a timing unit for
timing the switch on time and the switch off time of the switch
circuit, wherein the timing unit is configured to: i. compare the
switch on time and the switch off time with a preset intelligent
dimming interval time to generate a first comparison result; and
ii. compare the switch on time and the switch off time with a
preset latch interval time to generate a second comparison result;
b. a pulse trigger unit, wherein the pulse trigger unit is
connected to the timing unit, wherein the pulse trigger unit is
configured to generate a pulse trigger signal based on the first
comparison result and the second comparison result; c. a latch
unit, wherein the latch unit saves the pulse trigger signal; and d.
a light source driving unit, wherein the light source drive unit is
connected to the pulse trigger unit and the latch unit, and is
configured to generate a light source drive signal based on the
pulse trigger signal.
2. The light source driving circuit of claim 1, wherein the light
dimming circuit further comprises: a latch reset unit, wherein the
latch reset unit is connected to the timing unit and the latch
unit, wherein the latch reset unit is configured to reset the latch
unit according to the second comparison result.
3. The light source driving circuit of claim 1, wherein the light
dimming circuit further comprises: a display circuit, wherein the
display circuit is connected to the pulse trigger unit, wherein the
display circuit generates a pair of display signals to illuminate
an indicator light.
4. The light source driving circuit of claim 1, wherein the light
dimming circuit further comprises a leakage protection safety
circuit, wherein the leakage protection safety circuit is
configured to: a. sample a voltage and a current of the power
supply to generate a grid impedance value; b. compare the grid
impedance value with a preset impedance threshold; and c. control a
connection state between the light source module and the power
supply.
5. The light source driving circuit of claim 1, wherein the leakage
protection safety circuit comprises: a. a voltage sampling unit,
wherein the voltage sampling unit is configured to sample voltage
on the power supply to generate a voltage sampling signal; b. a
current sampling unit, wherein the current sampling unit is
configured to perform current sampling on the power supply to
generate a current sampling signal; wherein the leakage protection
safety circuit is connected to the voltage sampling unit and the
current sampling unit, wherein the leakage protection safety
circuit is configured to receive a voltage sampling signal and a
current sampling signal to generate a grid impedance value, wherein
the grid impedance value is compared with a preset impedance
threshold, wherein a leakage protection signal is generated
according to the grid impedance value, wherein the leakage
protection signal adjusts the light source driving signal.
6. The light source driving circuit of claim 5, wherein the leakage
protection safety circuit further comprises: a leakage switch unit,
wherein the leakage switch unit is connected to the leakage
protection unit and receives the leakage protection signal and
controls a connection state between the light source module and the
power supply according to the leakage protection signal.
7. The light source driving circuit of claim 1, wherein the power
switch is a wall switch.
Description
FIELD OF THE INVENTION
The present invention relates to the field of lighting, in
particular to a driving and dimming circuit.
DISCUSSION OF RELATED ART
As LED lamps have improved over time, they have replaced
fluorescent lamps in general lighting applications. With higher
high luminous efficiency and low energy consumption, LED lamps are
now popular for general lighting in homes and businesses. This new
found popularity has increased demand for dimmable control in LED
products. At present, the dimming methods applied to LED lighting
products generally include: SCR dimming, remote control dimmers,
wall switches, and some commercial lighting dimming systems, such
as 0-10V, etc. However, the straight tube format LED lamp, which is
widely used in commercial lighting, has problems such as poor
dimming mode compatibility and sudden light output changes in
different modes, which limits use of the straight tube format LED
lamp.
The current state-of-the-art of thyristor dimming, wireless dimming
(including Bluetooth, WIFI, Ziggbee, infrared, microwave, etc.),
and switch-controlled segmented dimming can all be used on
straight-tube LED lights. These techniques have drawbacks, for
example for the thyristor dimming method, the power factor will
become very poor under light load conditions. Other techniques
create light output jitter and dimming noise pollution.
Furthermore, for the North American market, there are different
types of household current, namely 120V AC and there are two kinds
of lighting grids with 277V alternating current, and the thyristor
dimming method is less suitable for dimming control under 277V
lighting conditions. The wireless dimming method has achieved good
results in the dimming effect. However, wireless dimming requires
the help of a dedicated dimming controller or an APP of an
electronic device (such as a mobile phone) to adjust the output,
which has a high application cost. Another important constraint is
that, because it is wireless dimming, a wireless communication
module needs to be built into each product. The price of wireless
communication modules is relatively high, resulting in a
substantial increase in the unit price of the finished product. For
switch segment dimming, it is obvious that its dimming state has
only a few modes (usually 3 to 4 modes), that is, the difference in
light output between different modes is very large which is to
abrupt light output change.
SUMMARY OF THE INVENTION
To solve the above technical problems, the embodiments of the
present application provide a light source driving circuit and a
light source driving circuit. An object of the invention is to
improve the light dimming circuit and solve some of the problems
currently facing linear LED lamps in commercial lighting, such as
poor dimming mode compatibility and sudden light output changes
during mode change.
The first aspect of the present application provides a light source
driving circuit capable of continuous dimming, which is connected
to the light source module, and the light source driving circuit
includes: a switch circuit, a turn on time and turnoff time of the
circuit, a signal, a timing unit, a preset smart dimming interval
time, a pulse trigger unit, and a latch unit. The power switch is
connected to the power supply and is used to turn on and off
according to user operations. The drive circuit is respectively
connected to the power switch and the light source module to detect
the switch. The turn-on time and turn-off time of the circuit,
generates a light source driver according to the turn-on time and
the turn-off time. A signal drives the light source module to light
up. The light source drive signal is used to adjust the brightness
of the light source module.
Optionally, the driving circuit includes a timing unit for timing
the on time and off time of the switch circuit. Comparing the on
time with a preset smart dimming interval time can generate a first
comparison result. Comparing the off time with the preset state
latch interval time can generate a second comparison result. A
pulse trigger unit connected to the timing unit is preferably
configured to generate a pulse trigger signal according to the
first comparison result and the second comparison result. A latch
unit records the pulse trigger signal. A light source drive unit is
connected to the pulse trigger unit and the latch unit, and records
the pulse trigger signal. The pulse trigger signal generates a
light source drive signal.
Optionally, the driving circuit further includes a latch reset unit
that is connected to the timing unit and the latch unit, and
configured to perform according to the second comparison result.
The comparison result performs a reset processing on the latch
unit. Optionally, the light source driving circuit includes: a
display circuit, connected to the pulse trigger unit, and
configured to generate a pair according to the pulse trigger
signal.
The corresponding display signal drives the indicator light to
light up. Optionally, the light source driving circuit includes a
leakage protection safety circuit, configured to perform voltage
sampling and current sampling on the power supply. The grid
impedance value is compared with a preset impedance threshold
value, and the connection state between the light source module and
the power supply is controlled according to the comparison
result.
Optionally, the leakage protection safety circuit includes: a
voltage sampling unit configured to perform voltage sampling on the
power supply to generate a voltage sampling signal; and a current
sampling unit configured to perform current sampling on the power
supply to generate a current sampling signal. The leakage
protection unit is respectively connected to the voltage sampling
unit and the current sampling unit. The voltage sampling signal and
the current sampling signal generate a grid impedance value. The
preset impedance threshold is compared, and a leakage protection
signal is generated according to the comparison result to adjust
the light source driving signal. Optionally, the leakage protection
safety circuit further includes a leakage switch unit connected to
the leakage protection unit and configured to receive the leakage
protection signal. According to the leakage protection signal, the
connection state between the light source module and the power
supply is controlled.
Optionally, the power switch is a wall switch. An embodiment of the
present application also provides a light source driving device.
The embodiment of the present application also provides a lamp. The
lamp includes a light source module. The light source drive circuit
is c preferably connected to the light source module pick up.
The embodiment of the present application provides a light source
driving circuit, a light source driving device and a lamp capable
of continuous dimming. The continuous light dimming circuit
receives an input from the turn-on and turn-off of the switch
circuit. The turn-on time and turn-off time of the turn-off circuit
are detected, and a light source drive signal is generated
according to the turn-on time and the turn-off time to drive the
light source module to light. The light source drive signal is used
to control the brightness of the light source module, and adjust
the brightness of the light source module by turning on and off the
switch circuit, which solves the problem of poor dimming
compatibility and light output in different gears for straight-tube
LED lamps that are more commonly used in commercial lighting.
Problems such as sudden changes have greatly restricted the
application scenarios of straight-tube LED lights.
The LED light has gradually replaced traditional light sources due
to low energy consumption, no pollution, no mercury, and long life.
Demand for dimmable control in LED products is becoming
increasingly urgent.
The make the technical problems, technical solutions, and
beneficial effects to be solved by this application clearer, the
following further describes this application in detail with
reference to the accompanying drawings and embodiments. It should
be understood that the specific embodiments described here are only
used to explain the application, but not to limit the application.
It should be noted that when an element is referred to as being
"fixed to" or "disposed on" another element, it can be directly on
the other element or indirectly on the other element. When an
element is said to be "connected to" another element, it can be
directly connected to the other element or indirectly connected to
the other element. It should be understood that the terms "length",
"width", "upper", "lower", "front", "rear", "left", "right",
"vertical", "horizontal", "top" The orientation or positional
relationship indicated by "bottom", "inner", "outer", etc. is based
on the orientation or positional relationship shown in the
drawings, and is only for the convenience of describing the
application and simplifying the description, and does not indicate
or imply the pointed device or the element must have a specific
orientation, be constructed and operated in a specific orientation,
and therefore cannot be understood as a limitation of the
application. In addition, the terms "first" and "second" are only
used for descriptive purposes, and cannot be understood as
indicating or implying relative importance or implicitly indicating
the number of technical features indicated. Therefore, the features
defined with "first" and "second" may explicitly or implicitly
include one or more of these features. In the description of this
application, "plurality" means two or more, unless otherwise
clearly defined.
SUMMARY OF THE CLAIMS
A light dimming circuit has a continuous dimming function that
includes a power supply and a light source module formed as a lamp.
A power switch is connected to a power supply and receives a user
input when the user turns on and turns off power. A light source
drive circuit is connected to the power switch and the light source
module. The light source drive circuit detects a switch on time and
a switch off time, generates a light source drive signal according
to the switch on time and the switch off time, and saves the light
source drive signal and drives the light source module to
illuminate.
The light source drive signal controls a brightness of the light
source module. The brightness of the light source module is
adjusted to provide a continuous dimming function according to the
switch on time and the switch off time.
Optionally, the light source driving circuit also includes a timing
unit for timing the switch on time and the switch off time of the
switch circuit. The timing unit is configured to compare the switch
on time and the switch off time with a preset intelligent dimming
interval time to generate a first comparison result. The timing
unit also compares the switch on time and the switch off time with
a preset latch interval time to generate a second comparison
result. A pulse trigger unit is connected to the timing unit is
configured to generate a pulse trigger signal based on the first
comparison result and the second comparison result.
A latch unit saves the pulse trigger signal. A light source driving
unit is connected to the pulse trigger unit and the latch unit and
generates a light source drive signal based on the pulse trigger
signal. The light dimming circuit has a latch reset unit connected
to the timing unit and the latch unit. The latch reset unit resets
the latch unit according to the second comparison result. The light
dimming circuit may have a display circuit connected to the pulse
trigger unit. The display circuit generates a pair of display
signals to illuminate an indicator light.
The light dimming circuit may have a leakage protection safety
circuit that samples a voltage and a current of the power supply to
generate a grid impedance value. The leakage protection safety
circuit also compares the grid impedance value with a preset
impedance threshold and controls a connection state between the
light source module and the power supply. The leakage protection
safety circuit preferably includes a voltage sampling unit. The
voltage sampling unit is configured to sample voltage on the power
supply to generate a voltage sampling signal. A current sampling is
configured to perform current sampling on the power supply to
generate a current sampling signal. The leakage protection safety
circuit is connected to the voltage sampling unit and the current
sampling unit. The leakage protection safety circuit is configured
to receive a voltage sampling signal and a current sampling signal
to generate a grid impedance value. The grid impedance value is
compared with a preset impedance threshold. A leakage protection
signal is generated according to the grid impedance value. The
leakage protection signal adjusts the light source driving
signal.
The leakage protection safety may also have a leakage switch unit.
The leakage switch unit is connected to the leakage protection unit
and receives the leakage protection signal to control a connection
state between the light source module and the power supply
according to the leakage protection signal. The power switch can be
a standard two gang toggle wall switch.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of the continuous light dimming
circuit.
FIG. 2 is a schematic flow diagram of the dimming step performed by
the driving circuit provided by an embodiment of the
application.
FIG. 3 is a block diagram of the continuous light dimming
circuit.
FIG. 4 is a block diagram of the continuous light dimming
circuit.
FIG. 5 is a circuit diagram of the continuous light dimming
circuit.
FIG. 6 is circuit diagram of the continuous light dimming
circuit.
FIG. 7 is circuit diagram of the continuous light dimming
circuit.
The following callout list of elements can be a useful guide in
referencing the element numbers of the drawings. 10 power supply 20
power switch 30 light source driving circuit 31 timing unit 32
pulse trigger unit 33 latch unit 34 light driver 35 latch reset
unit 40 light source module 50 display circuit 60 electrical
leakage protection path 81 circuit 82 leakage protection circuit 83
main control circuit 84 power supply circuit 85 main power circuit
101 Switch Activation 102 Recall dimming setting 103 Light Level
reached? 104 intelligently adjust dimming 105 Define dimming
setting as 100% lamp brightness 106 Save dimming setting 107 Light
Switched Off 108 Second Switch Activation 109 Recall Of The Storage
Gap Setting BD1 rectifier bridge COMP compensation signal pin CS
current sampling terminal C1 capacitor C2 second capacitor C10
tenth capacitor C11 eleventh capacitor C12 twelfth capacitor C13
thirteenth capacitor C14 Fourteenth capacitor C15 fifteenth
capacitor C16 sixteenth capacitor C17 seventeenth capacitor C18
eighteenth capacitor C19 nineteenth capacitor C20 twentieth
capacitor C21 twenty-first capacitor CLK clock signal terminal DC
output high-voltage D1 first diode D2 second diode D10 tenth diode
D11 eleventh diode D12 twelfth diode D13 thirteenth diode D14
fourteenth diode DRAIN input pin EC1 first terminal of the first
electrolytic capacitor F1 first fuse GATE light source drive signal
pin GND ground pin LED+ positive terminal PWM signal input pin Q1
first switch tube Q10 tenth switch tube Q11 eleventh switch tube
Q12 twelfth switching tube L1 first inductor L2 second inductor NP
sampling pin R1 first resistor R2 second resistor R3 third resistor
R5 fifth resistor R6 sixth resistor R7 seventh resistor R8 eighth
resistor R9 ninth resistor R10 tenth resistor R11 eleventh resistor
R12 twelfth resistor R13 thirteenth resistor R14 fourteenth
resistor R15 fourteenth resistor R16 sixteenth resistor R17
seventeenth resistor R18 eighteenth resistor R19 nineteenth
resistor R20 twentieth resistor R21 twenty-first resistor 22
twenty-second resistor R23 twenty-third resistor R24 24th resistor
R25 25th resistor R26 26th resistor R27 27th resistor R28 28th
resistor R29 29th resistor R30 30th resistor R31 Thirty-first
resistor R32 thirty-second resistor RS1 first sampling resistor RS2
second sampling resistor RS3 first end of the sampling resistor RS4
fourth sampling resistor T1-A first inductor T1-B second inductor
T1 first transformer U1 light source drive chip U2 sampling drive
chip U3 leakage protection chip U4 Control chip U5 power supply
chip U6 main power chip VCC power supply pin VCC2 output terminal
VR variable resistor VSS the ground pin ZD10 tenth voltage
regulator ZD11 eleventh voltage regulator
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention is a continuously dimming circuit for a
driver and a lamp. As seen in FIG. 1 a block diagram of a light
source driving circuit 30 is an LED driver circuit capable of
continuous dimming according to an embodiment of the application.
As shown in FIG. 1, the light source driving circuit 30 is
connected to the light source module 40. Specifically, the light
source driving circuit 30 includes a switch. The power switch 20 is
connected to the power supply 10 for turning on and off according
to user input. The light source drive circuit 30 is connected to
the power switch 20 and the light source module 40 for detecting
the power switch 20.
The light source drive signal is generated according to the on time
and the off time to drive the light source module 40 to light up.
The light source drive signal is used to adjust the brightness of
the light source module 40. For example, the power switch 20 is
performing open-close-open modulation which could be pulse width
modulation. During operation, its first turn-on time, that is the
turn-on time of the power switch 20, has the same turn-on time set
from a previous use. The corresponding light source drive signal
corresponds to a brightness setting, for example, if the open time
range is 10 ms-10000 ms, then each point between 10 ms and 10000 ms
can correspond to a light source drive signal. For example, with an
interval of 1 ms, the light source module 40 has 9990 brightness
levels.
Further, the user can also input the corresponding opening time
through the input component to control the time length of the first
opening time of the power switch 20 during the
opening-closing-opening operation. If the user inputs 1000 ms and
the timer reaches 1000 ms, the power switch 20 is automatically
turned off at this time, and the drive circuit 30 records the
signal generated based on the on time before the power switch 20 is
turned off, and when it turns on again within the preset time the
corresponding light source driving signal is generated based on the
signal to drive the light source module 40 to light, and there is
no need to manually perform the opening action at this time, so as
to avoid the time error caused by the user manually performing the
opening action.
In this application, by controlling the on and off of the power
switch 20, the drive circuit 30 generates a corresponding light
source drive signal based on the on time and off time, and adjusts
the brightness of the light source module 40, so as to achieve
continuous adjustment.
The user can set a dim light by quickly flicking on and off the
switch, thus effectively sending a single pulse width modulation
signal which is stored for reference. The user can set a brighter
light, by turning on the switch, and then waiting a ten seconds
before turning off the switch. The light starts dim and becomes
brighter to give the user a reference of how bright the light is
until the user sets the light brightness by turning off the light.
When the user turns the light back on again, the light is preset at
the previous dimming level.
The power switch 20 can be a wall switch with a toggle such as a
decora style toggle. In addition to the function of turning on and
off the current on the power line in our traditional sense, the
power switch 20 also has an important function, which is to turn
on-off through a switch. The off-on operation sequence, and based
on the time interval of different lengths between the corresponding
actions, generates the corresponding light source driving signal.
In this embodiment, the driving circuit 30 is a key core circuit,
which is connected to the lamp holder to convert the energy in the
AC power grid, and at the same time, it receives the signal from
the power switch 20, and recognizes and converts the switching
signal of the power switch 20. As an internal control signal, the
output of the driving circuit 30 is adjusted to transfer energy to
the light source module 40 according to the predetermined
requirements, so as to effectively control the brightness of the
light source module 40.
The present invention allows easy retrofitting because the original
switch does not need to be changed. Only the lamp needs to be
retrofit, which does not affect the wiring. In the example, the
light source module 40 with the drive circuit 30 is installed, and
then the light source module 40 can be continuously dimmed using
the same switch. Specifically, in the present application, the
switching circuit 20 is used to perform the on or off operation,
thereby introducing the general state switching time interval. Then
the drive circuit 30 generates the light source drive signal based
on the on time and off time of the power switch 20.
To adjust the brightness of the light source module 40, when the
power switch 20 performs the operation "turn on-turn off-turn on",
there is a time between when the power switch 20 is turned on to
when it is turned off. It is called the "smart dimming interval".
From the power switch 20 is turned off to the power switch 20 is
turned on again, there is a period of time called the "state latch
interval". When the user executes the power switch 20, the turn-on
and turn-off operations are combined with the interval time of the
two operations at the same time to generate different combinations,
and the subsequent drive circuit 30 generates corresponding light
source drive signals based on the different time combinations.
As seen in FIG. 2, the logic of the continuous light dimming
circuit begins at switch activation 101. The dimming setting
increases or decreases light level until a desired light level is
reached 103. The control system then recalls dimming setting 102
when the light level is reached. Until the light level is reached,
the circuit intelligently adjusts dimming the level 104. When the
dimming gap setting is reached, the light is switched off 107 which
saves the dimming setting and defines the setting as 100% lamp
brightness 105. The second switch activation 108 activates a recall
of the storage gap setting 109. If the time between the switch off
and the second switch activation reached the storage gap setting
which is a set amount of time, then the memory can be cleared or
the logic can recall the dimming setting and keep the brightness
105. If the memories cleared, the light level reached 103 continues
to operate.
The driving circuit 30 performs a dimming step based on the state
switching of the power switch 20. Specifically, the power switch 20
can be a wall switch and a light source module 40 can be an LED
tube. When the LED tube is required to work at 100% full
brightness, the wall switch is turned on (that is, the power switch
20 is in the on state), the LED light enters the intelligent
dimming stage, and the brightness continues to increase. Without
any intervention (that is, no action is performed on the power
switch 20 at this time), after the smart dimming time ends, the on
time of the power switch 20 reaches the preset smart dimming
interval, and the LED lights are at full brightness output and keep
the current working state.
If it is in some specific occasions that the LED light needs to be
controlled at a fixed brightness to work continuously, after the
wall switch is turned on, the user observes the brightness of the
LED light. In the dimming mode, during this short period of time in
the entire smart dimming interval, the LED lights continue to
increase in brightness from the lowest brightness to the highest
brightness. When the desired state is reached, the wall switch is
turned off. The dimming state at the turnoff time is recorded. The
LED light output before the power disconnection is saved. The
current and voltage corresponding to the brightness of the LED
light before the power turnoff are preferably saved. If the wall
switch is turned on again within the state latch interval, the
light reverts to the saved settings. When the circuit 30 is powered
on, the LED lamp tube maintains a locked state to work. The LED
lamp is driven to light up according to the current and voltage
corresponding to the brightness of the LED lamp before the power is
turned off, thereby completing the adjustment of the brightness of
the LED lamp.
In one embodiment, referring to FIG. 3, the driving circuit 30 in
this embodiment includes a timing unit 31. Pulse trigger unit 32,
latch unit 33, and light source drive unit 34, specifically, timing
unit 31 is used to time the on time and off time of the power
switch 20, and compare the on time with the preset smart dimming
interval time to generate the first comparison result, and lock the
off time with the preset state. The device stores the interval time
for comparison to generate the second comparison result. The pulse
trigger unit 32 is connected to the timing unit 31 to generate
pulse trigger signals according to the first comparison result and
the second comparison result. The latch unit 33 is used to record
pulse trigger signals. The light source driving unit 34 is
connected to the pulse trigger unit 32 and the latch unit 33 and is
used to trigger signals according to the pulse generated light
source drive signal.
The timing unit 31 counts the on time and off time of the power
switch 20, and compares the on time with the preset smart dimming
interval time to generate the first comparison result. The pulse
trigger unit 32 generates a corresponding pulse trigger signal
based on the first comparison result and the second comparison
result. The latch unit 33 records the pulse trigger signal, and the
light source driving unit 34 generates a light source driving
signal based on the pulse trigger signal to reduce the brightness
of the light source module 40.
To make adjustments for example, if the on-time of the power switch
20 is greater than or equal to the preset smart dimming interval
time, the pulse trigger unit 32 generates a corresponding pulse
trigger signal based on the first comparison result, and the latch
unit 33 latches and records. If the parallel light source driving
unit 34 generates a corresponding light source driving signal based
on the pulse trigger signal, it controls the light source module 40
to maintain a state of 100% brightness. If the on time of the power
switch 20 is less than the preset intelligent dimming interval
time, the timing unit 31 re-times the off time of the power switch
20, and if the off time is less than the preset state latch
interval time, the pulse trigger unit 32 generates a corresponding
pulse trigger signal based on the second comparison result, and the
latch unit 33 records the pulse trigger signal. This happens when
the power switch 20 is turned on within the preset state latch
interval time.
The pulse trigger signal and the switch define a desired
brightness. The brightness of the light source module 40 before the
circuit 20 is disconnected corresponds to the preset light level.
The light source driving unit 34 corresponds to the light source
drive signal. The corresponding light source drive signal is based
on the pulse trigger signal to drive the light source module 40 to
light up with the preset brightness before the power switch 20 is
disconnected. The light source module 40 thus has adjustable
brightness.
As seen in FIG. 4, the driving circuit 30 in this embodiment
further includes a latch reset unit 35, which is connected to the
timing unit 31 and the latch unit 33. The latch reset unit 35 works
with the timing unit and the pulse trigger unit 32 to reset the
latch unit 33. If the timing unit 31 re-times the turn-off time of
the power switch 20, and the turn-off time is greater than or equal
to the preset state latch interval time, the pulse trigger unit 32
generates a corresponding pulse trigger signal based on the second
comparison result, and the latch unit 33 records the pulse trigger
signal so that the latch reset unit 35 resets the latch unit 33.
This clears the latch unit 33 so that a user can reset another
dimming level. The dimming step of the drive circuit 30 is
interrupted, and the drive circuit 30 needs to execute again as
shown in FIG. 2 which shows the steps of defining a present dimming
level.
As shown in FIG. 4, the light source driving circuit 30 includes a
display circuit 50, which is connected to the pulse trigger unit
32, and is configured to generate a corresponding display signal
according to the pulse trigger signal to drive the indicator light
to light up. In this embodiment, the display circuit 50 generates a
corresponding display signal based on the pulse trigger signal to
drive the indicator light. For example, if the on time of the power
switch 20 is less than the preset smart dimming interval time, the
pulse trigger unit 32 generates a corresponding pulse trigger
signal based on the conduction time of the power switch 20. The
pulse trigger signal corresponds to the brightness of the light
source module 40. The longer the conduction time, the greater the
brightness of the light source module 40.
Optional indicator lights can provide remote operation. Instead of
having the brightness of the light source module 40 judged based
solely on the naked eye, the current brightness of the light source
module 40 can be determined by providing multiple indicator lights
or based on a color of the indicator lights, so as to select the
appropriate brightness to turn off the power switch 20. The
conduction time of the power switch 20, for example, if 20
indicator lights are set, the user can judge the brightness of the
light source module 40 at this time by the number of indicator
lights, or the indicator light can be set in the form of a light
bar. By observing the progress of the light bar, the current
brightness of the light source module 40 is determined. Further,
judging the condition of the light source module 40 by the
indicator light can also allow remote operation away from the light
source module 40. After the user disconnects the power switch 20,
the brightness of the light source module 40 before the power
switch 20 is disconnected is latched and recorded by the latch unit
33. When the power switch 20 is turned on, the light source drive
unit 34 reads the latched pulse trigger signal, and generates a
corresponding light source drive signal based on the pulse trigger
signal.
Alternatively, the wall switch can have a dimming status display,
and the display circuit 50 can be an LED indicator. The dimming
status can be is displayed through the indicator. The timing unit
31, the pulse trigger unit 32, and the latch unit 33 can all be
placed inside a housing of the wall switch, and the indicator light
can be installed on the surface of the wall switch. The intelligent
dimming interval time and the status latch interval time are preset
in the timing unit 31, and the pulse trigger unit 32 drives the LED
indicator to reflect the current LED light. The latch unit 33 can
temporarily store the preset level in the pulse trigger unit 32
when the wall switch 20 is turned off.
The main power switch also called the power switch 20 is turned on,
the display circuit 50 starts at the same time, and the timing unit
31 starts timing. During the smart dimming interval, the light
output of the LED tube increases smoothly from the lowest
brightness. For example, when the brightness reaches 10%, the pulse
trigger unit 32 drives the first indicator light to light up. Wen
the brightness reaches 20%, the second indicator light also lights
up and so on until the time reaches the intelligent dimming
interval when the LED output is at 100% brightness, and the
corresponding ten indicator lights are all remaining on.
When the brightness of the LED tube needs to be selected, the
indicator shows the corresponding state. The user turns off the
wall switch, and the drive signal of the pulse trigger unit 32 (aka
the pulse trigger signal) is placed in the latch unit 33. At this
time, the timing unit 31 starts timing again. Before reaching the
state latch interval of the LED tube, the wall switch is turned on,
and the pulse trigger unit 32 reads the recorded value from the
latch unit 33 and drives the indicator light on the display circuit
50. The lamp tube also continues to work according to the
brightness before the power failure, so as to implement the
correspondence between the LED lamp brightness output and the
indicator light display.
In one embodiment, the light source driving circuit 30 includes a
leakage protection safety circuit. The leakage protection safety
circuit is used to sample the voltage and current of the power
supply 10 to generate a grid impedance value, and compare the grid
impedance value with a preset impedance threshold. The light source
module 40 with the power supply 10 controls the connection status.
In this embodiment, the voltage sampling and current sampling of
the power supply 10 are performed by the leakage protection safety
circuit. Sampling is used to generate the grid impedance value. The
grid impedance value is compared with a preset impedance threshold.
The connection state between the light source module 40 and the
power supply 10 is controlled according to the comparison
result.
Optionally, the leakage protection safety circuit includes a
voltage sampling unit, a current sampling unit, and a leakage
protection unit. The voltage sampling unit is used to perform
voltage sampling on the power supply 10 to generate a voltage
sampling signal. The current sampling unit is used to perform
current sampling and generate a current sampling signal. The
leakage protection unit is respectively connected with the voltage
sampling unit and the current sampling unit, and is used to
generate the grid impedance value according to the voltage sampling
signal and the current sampling signal. Comparing the grid
impedance value with the preset impedance threshold provides a
comparison result. The comparison result generates a leakage
protection signal to adjust the light source driving signal.
In an embodiment, the leakage protection safety circuit further
includes a leakage switch unit, and the leakage switch unit
connected to the leakage protection unit, used to receive the
leakage protection signal. The leakage protection signal to the
light source module controls the connection state between the light
source module 40 and the power supply 10.
The physical construction of the power switch 20 can be a wall
switch, for example, a 86-type, 118-type panel switch, and a
rotary, rocker, push, or touch wall switch. In the application of
this technology, the wall switch is not limited to its specific
form, and it only needs to be able to provide an on-off
function.
In a specific embodiment, referring to FIG. 5, the leakage
protection safety circuit 60 includes: a seventh resistor R7, an
eighth resistor R8, a ninth resistor R9, a tenth resistor R10, a
second capacitor C2, a first sampling resistor RS1, a second
sampling resistor RS2 and the sampling drive chip U2. The power
supply terminal VDD of the sampling drive chip U2 is connected to
the first end of the second capacitor C2 and the first end of the
tenth resistor R10. The second end of the tenth resistor R10 is
connected to the first end of the ninth resistor R9.
The second end of the ninth resistor R9 is connected to the wall
switch DB. The second end of the second capacitor C2 is grounded.
The voltage sampling terminal VS of the sampling drive chip U2 is
connected to the first end of the seventh resistor R7 and the first
end of the eighth resistor R8. The second end of the eighth
resistor R8 is grounded. The second end of the seventh resistor R7
is connected to the light source module 40. The ground terminal GND
of the sampling drive chip U2 is connected to ground. The current
sampling terminal CS of the sampling drive chip U2, is connected to
the first terminal of the first sampling resistor RS1, and the
first terminal of the second sampling resistor RS2 which are
connected together. The second terminal of the first sampling
resistor RS1 is connected to the second terminal of the second
sampling resistor RS2 and both are commonly connected to ground.
The driving signal terminal DRV of the sampling drive chip U2 is
connected to the second terminal of the seventh resistor R7 and the
anode of the second diode D2 as well as the first terminal of the
first electrolytic capacitor EC1 and the sixth resistor R6. The
first end of the light source module 40 is connected to the
negative terminal LED-.
The seventh resistor R7 and the eighth resistor R8 constitute a
voltage sampling unit. The first sampling resistor RS1 and the
second sampling resistor RS2 constitute a current sampling unit.
The sampling drive chip U2 serves as a leakage protection unit that
calculates the equivalent impedance Zs of the grid. In general, the
equivalent impedance of the power grid is between a few ohms to a
dozen ohms. The equivalent impedance of the human body is roughly
equal to 500 ohms. In the process of engineering installation and
disassembly, the leakage protection safety circuit detects and
calculates the equivalent impedance of the access point in real
time. When the equivalent impedance Zs is less than the set value,
it is determined that no human body is in contact with the power
grid, and its built-in switch close circuit 20 (that is, the
leakage switch unit) is closed, and the LED tube is normally
connected. On the other hand, if the equivalent impedance Zs is
greater than when the value is set, it is determined that a human
body is in contact with the power grid, and its built-in power
switch 20 will be turned on, and the LED tube will be disconnected
from the power grid, thus avoiding electric shock.
Also as seen in FIG. 5, the driving circuit 30 includes a first
resistor R1, a second resistor R2, a third resistor R3, a fifth
resistor R5, a second inductor T1-B, a third sampling resistor RS3,
and a fourth sampling resistor RS4, the first switch tube Q1, the
first capacitor C1, and the light source drive chip U1. The first
end of the first resistor R1, the high voltage input terminal HV of
the light source drive chip U1, and the current of the first switch
tube Q1 are connected to the input terminal and connected to the
power switch 20. The second terminal of the first resistor R1 is
connected to the first terminal of the second resistor R2. The
second terminal of the second resistor R2 and the first terminal of
the third resistor R3 are commonly connected to the light source
driving chip and the clock signal terminal CLK of U1. The power
terminal of the light source driving chip U1, the cathode LED of
the first diode D1 and the first terminal of the first capacitor C1
are connected in common. The anode of the first diode D1 is
connected to the fifth resistor R5. The first end of the fifth
resistor R5 is connected to the first end of the second inductor
T1-B. The second end of the second inductor T1-B, the second end of
the third resistor R3, and the first capacitor and the second
terminal of C1 are connected in common. The drive signal terminal
DRV of the light source drive chip U1 is connected to the control
terminal of the first switch tube Q1.
The current sampling terminal CS of the light source drive chip U1
is connected to the current output terminal of the first switch
tube Q1, the first end of the third sampling resistor RS3, the
first end of the fourth sampling resistor RS4, and the cathode of
the second diode D2. The ground terminal GND of the light source
driving chip U1 is grounded. The second end of the third sampling
resistor RS3 and the second end of the fourth sampling resistor RS4
is connected to the first end of the first inductor T1-A. The
second end of the first inductor T1-A is connected to the second
end of the first electrolytic capacitor EC1, and the second end of
the sixth resistor R6, which are commonly connected to the positive
terminal LED+ of the light source module 40.
The first resistor R1, the second resistor R2, and the third
resistor R3 form a sampling circuit to detect the on and off of the
power switch 20. The light source drive chip U1 has a built-in
timing unit 31. The pulse trigger unit 32, the latch unit 33, and
the light source drive unit 34 operate according to the state of
the power switch 20. The light source drive signal is generated at
the first turn-on time in the turn-on-turn-turn-on operation to
adjust the brightness of the light source module 40.
As seen in FIG. 6, the light source driving circuit in this
embodiment may also include a rectifier circuit 81. Specifically,
the rectifier circuit 81 is connected to the power supply 10 having
a load line and neutral line. The rectifier circuit 81 filters and
rectifies the output AC signal. The fuse F1 is connected to the
live wire output terminal L of the power supply 10. The tenth
capacitor C10 is connected in parallel with the power supply
10.
Rectifier bridge BD1 and fuse F1 are both connected to rectify the
AC power. The resistor R10, the variable resistor VR, the first
inductor L1, the eleventh capacitor C11, and the twelfth capacitor
C12 form a it-type filter circuit to filter the output signal after
rectification.
Also as shown in FIG. 6, the leakage protection circuit 82 is
another leakage protection safety circuit provided by this
embodiment of the application, in which the tenth diode D10, the
eleventh resistor R11, and the twelfth resistor R12 are
sequentially connected to form a signal acquisition circuit. The
circuit is connected to the input pin RCC of the leakage protection
chip U3. The output pin EN of the leakage protection chip U3 is
connected to the control terminal of the tenth switch tube Q10
through the thirteenth resistor R13, and the current input terminal
of the tenth switch tube Q10. The fourteenth resistor R14 is
connected to the power pin of the leakage protection chip U3. The
current output end of the tenth switch tube Q10 and the first end
of the fifteenth resistor R15 are connected to the control end of
the eleventh switch tube Q11. The second end of the fifteenth
resistor and the first end of the thirteenth capacitor C13, the
ground pin GND of the leakage protection chip U3, and the current
output end of the eleventh switch tube Q11 are connected to the
ground and the second end of the thirteenth capacitor C13. The
terminal is connected to the power supply pin VCC of the leakage
protection chip U3.
The leakage protection circuit 82 collects the voltage signal in
the power supply 10 through the signal acquisition circuit, and
calculates the equivalent impedance Zs of the power grid. In
general, the equivalent impedance of the power grid is between a
few ohms to a dozen ohms whereas the equivalent impedance of the
human body is roughly equal to 500 ohms. In the process of
engineering installation and disassembly, the leakage protection
safety circuit detects and calculates the equivalent impedance of
the access point in real time. If the equivalent impedance Zs is
less than the set value, it is determined that no human body is in
contact with the power grid. At this time, the level of the output
pin EN is high on the leakage protection chip U3, the tenth
switching tube Q10 is turned off, and the eleventh switching tube
Q11 is turned off The output signal of the leakage protection
circuit 82 does not affect the PWM signal of the output terminal of
the main control circuit 83, and the LED lights and thus the tube
is normally connected. On the other hand, if the equivalent
impedance Zs is greater than the set value, it is determined that a
human body is in contact with the power grid. At this time, the
level of the output pin EN of the leakage protection chip U3 is
high, and the tenth switching tube Q10 is turned off. The eleventh
switching tube Q11 is turned on, and the leakage protection circuit
82 pulls the PWM signal of the output terminal of the main control
circuit 83 to ground, and the LED tube is disconnected from the
power grid, thereby avoiding electric shock. The tenth switch tube
Q10 can be a PNP type transistor, and the eleventh switch tube Q11
can be an NPN type transistor.
As seen in FIG. 6, the main control circuit 83 and the main power
circuit 85 in can form a driving circuit. Specifically, the main
control circuit 83 detects the on time and off time of the switch
circuit and generates a dimming signal according to the on time and
the off time. The main power circuit 85 generates a light source
driving signal according to the dimming signal to drive the light
source module to light. The main control circuit 83 may have a
timing unit, a pulse trigger unit, and a latch unit. The pulse
trigger signal may be sent to the main power circuit 85 as a
dimming signal, and the main power circuit 85 may be the light
source de-drive unit that generates the light source drive signal
according to the pulse trigger signal number.
Specifically, in a specific application embodiment, referring to
FIG. 6, the main control circuit 83 includes a control chip U4,
sixteenth resistor R16, seventeenth resistor R17, eighteenth
resistor R18, nineteenth resistor R19, tenth voltage regulator
ZD10, twentieth resistor R20, eleventh voltage regulator ZD11, and
fourteenth capacitor C14. The first end of the sixteenth resistor
R16 is connected to the power supply 10, and the second end of the
sixteenth resistor R16 is connected to the first end of the
seventeenth resistor R17. The second end of the seventeenth
resistor R17, the first end of the eighteenth resistor R18, the
first end of the nineteenth resistor R19 and the cathode of the
tenth zener tube ZD10 are connected together. The second end of the
eighteenth resistor R18 is connected to the anode of the tenth
zener tube ZD10 which are commonly connected to ground. The second
end of the nineteenth resistor R19 is connected to the input pin IN
of the main control chip U4. The power supply pin of the main
control chip U4, the first end of the fourteenth capacitor, and the
eleventh voltage regulator tube, and the cathode of diode ZD11 are
connected to the power supply circuit 84. The anode of the eleventh
voltage regulator ZD11, the second end of the fourteenth capacitor
C14 and the ground pin VSS of the main control chip U4 are
connected together. The output pin of the main control chip U4 OUT
is connected to the main power circuit 85 through the twentieth
resistor R20.
In this embodiment, the main control chip U4 is used as the dimming
signal unit, in which the program is pre-installed, the sixteenth
resistor R16, the seventeenth resistor R17, the eighteenth resistor
R18, the nineteenth resistor R19, and the tenth diode ZD10 form a
signal acquisition circuit to detect the switch of the line. When
the wall switch is turned on, the main control chip U4 is powered
on, and the main control chip U4 outputs a PWM signal through its
output pin OUT to control the main power circuit 85 drive so that
the light source module lights up. Specifically, in the intelligent
dimming time interval, the PWM dimming signal will continue to
increase from 1% to 100%, and the corresponding constant current
drive unit (that is, the main power 85) obtains the dimming signal
from the PWM dimming interface and adjusts the output current
synchronously, so that the LED the lamp gradually increases from
the lowest brightness to 100% brightness.
If the wall switch is turned off during the smart dimming time
interval, that is, during the period when the dimming signal unit
outputs a changing PWM signal, the PWM signal before the system is
powered off will be temporarily latched. Similarly, if the wall
switch is turned on before the latch time interval arrives, the
system is powered on again. Then the dimming signal unit directly
outputs the PWM dimming signal latched before the system is powered
off. Correspondingly, the output brightness of the LED tube is also
the brightness before the system is powered off. In this way, the
LED tube can be selected from the lowest brightness to 100%
brightness. If the wall switch is turned on again after the latch
time interval is reached, the latch signal in the dimming signal
unit will be reset. At this time, the dimming signal unit will
enter the smart dimming time interval again, that is, the output
PWM signal will start over from 1% again and gradually increase
upward.
As seen in FIG. 6, the light source driving circuit may further
include a power supply circuit 84 used to convert the direct
current output by the rectifier circuit 81 into a power supply
signal to supply power to the main control circuit 83. The power
supply circuit 84 includes a power supply chip U5, an eleventh
diode D11, a twelfth diode D12, a fifteenth capacitor C15, and a
sixteenth capacitor C16, the seventeenth capacitor C17, the
twenty-first resistor R21, the twenty-second resistor R22, the
twenty-third resistor R23, and the second inductor L2. The anode of
the eleventh diode D11 connects to the rectifier circuit 81. The
cathode of the eleventh diode D11, the first end of the fifteenth
capacitor C15 and the input pin DRAIN of the power supply chip U5
are connected together.
The ground pin GND of the power supply chip U5, the first end of
the twenty-first resistor R21, and the first end of the
twenty-third resistor R23 are connected together. The second end of
the twenty-first resistor R21, the second end of the twenty-third
resistor R23, the first end of the second inductor L2, and the
first end of the sixteenth capacitor C16 are connected in common.
The output pin OUT of the power supply chip U5, the second end of
the sixteenth capacitor C16 and the cathode of the twelfth diode
D12 are connected in common. The second end and the second end of
the second inductor L2 are connected in common. The anode of the
twelve diode D12, the first end of the seventeenth capacitor C17,
and the first end of the twenty-second resistor R22 are commonly
connected. The output terminal VCC2 of the power supply circuit 84
is connected to the main control circuit 83.
The power supply chip U5 mainly performs voltage conversion on the
DC power output by the rectifier circuit 81, conversion processing,
and output the corresponding DC signal to supply power to the main
control circuit 83. The rectifier circuit 81 the output
high-voltage DC voltage is converted into a 5V DC signal to supply
power to the main control chip U4.
In a specific application embodiment, referring to FIG. 6, the main
power circuit 85 includes: a main power core chip U6, twenty fourth
resistor R24, twenty fifth resistor R25, twenty sixth resistor R26,
twenty seventh resistor R27, twenty eighth resistor R28, twenty
ninth resistor R29, thirtieth resistor R30, a thirty-first resistor
R31, thirty-second resistor R32, eighteenth capacitor C18,
nineteenth capacitor C19, twentieth capacitor C20, twenty-first
capacitor C21, fourteenth diode D14, thirteenth diode D13, twelfth
switching tube Q12 and the first transformer T1. The first terminal
of the twenty-fourth resistor R24, the cathode of the fourteenth
diode D14, and the first terminal of the twentieth capacitor C20
terminal and the first terminal of the thirty-second resistor R32
are commonly connected. The output terminal of the rectifier
circuit 81 and the positive input terminal LED+ of the light source
module 40, the second terminal of the twenty-fourth resistor R24
are commonly connected. The twenty-fifth resistor R25 is connected
to the twenty-fourth resistor R24. The second end of the
twenty-fifth resistor R25, the first end of the thirty-second
resistor R32, the first end of the eighteenth capacitor C18, and
the power pin VCC of the main power chip U6 are connected together.
The signal modulation pin ADM of the power chip U6 is connected to
the first end of the nineteenth resistor. The second end of the
eighteenth capacitor C18 and the second end of the nineteenth
capacitor C19 are both connected to the ground.
The pulse of the main power chip U6, and the wide modulation signal
input pin PWM are connected to the main control circuit 83. The
light source drive signal pin GATE of the main power chip U6 is
connected to the first end of the thirtieth resistor R30. The
second end of thirtieth resistor R30, the first end of a resistor
R31 and the control end of the twelfth switch tube Q12 are
connected together. The second end of the thirty-second resistor
R32 is connected to the cathode of the thirteenth diode D13. The
anode, the first end of the twenty-sixth resistor R26 and the first
end of the main winding of the first transformer T1 are connected
together. The second end of the main winding of the first
transformer T1 is grounded, and the current input end of the
twelfth switch tube Q12, the first end of the secondary winding of
the first transformer T1 and the anode of the fourteenth diode D14
are commonly connected. The second end of the secondary winding of
the first transformer T1, the second end of the twentieth capacitor
C20, and the second end of the thirty-two resistor R32 are
connected. The negative input of the light source module LED-, the
feedback pin FB of the main power chip U6, the first end of the
twenty-sixth resistor R26, and the second end of the twenty-seventh
resistor R27 are connected in common. The first end of the
compensation signal pin COMP of the main power chip U6 is connected
to the first end of the twenty-first capacitor C21. The sampling
pin SNP of the main power chip U6, the first end of the
twenty-eighth resistor R28, the first end of the twenty-ninth
resistor R29, the first end of the thirty-first resistor R31, and
the twelfth switch Q12 are connected together. The current output
terminal of the main power chip U6, the second end of the
twenty-eighth resistor R28, the second end of the twenty-ninth
resistor R29, and the second end of the twenty-first capacitor C21
are connected together.
A BUCK driving circuit is formed by the main power chip U6 and its
peripheral circuits. Specifically, the main power chip U6 receives
the dimming signal sent by the main attack circuit 83, and controls
the light source module 40 according to the dimming signal. The
operating voltage and operating current are adjusted so that the
brightness of the light source module 40 corresponds to the dimming
signal.
As shown in FIG. 7, the output terminal of the leakage protection
circuit 82 can also be connected to the power supply terminal VCC1
of the main power circuit 85, and the power supply terminal VCC1
can be connected to the power supply pin VCC of the main power chip
U5. If the user gets an electric shock, the leakage protection
circuit 82 pulls the output terminal of the power supply circuit 84
down to the ground, so that the main power circuit 85 is powered
off, the light source module 40 stops working, and its power supply
port is pulled down to the ground. This provides a safety circuit
to avoid potential electrical safety hazards.
The output terminal of the leakage protection circuit 82 may also
be connected to the output terminal VCC2 of the power supply
circuit 84. When a user gets an electric shock, the leakage
protection circuit 82 will power the circuit the output terminal of
84 is pulled down to ground. When the main control circuit 83 is
powered off, and its output terminal PWM stops outputting the
dimming signal, this further controls the main power circuit 85 to
power off.
The units described as separate components may or may not be
physically separate, as the components displayed by the unit may or
may not be a physical unit, that is, they may be located in one
place, or they may be distributed to multiple network units. Some
or all of the units can be selected according to actual needs to
achieve the purpose of the solution of the embodiment. In addition,
the functional units in the various embodiments of the present
application may be integrated into one processing unit, or each
unit may exist alone physically, or two or more units may be
integrated into one unit. The above-mentioned integrated unit can
be realized in the form of hardware or software functional
unit.
* * * * *